I found this post an hour or two ago and have spent a bit of time researching it. I have to conclude that I really like the idea and may look further into using it myself. As a web developer, this is something I may also need to know about in the future, so thanks for bringing it to my attention.
On a related note, what do you think of the
Pavatar? Looks like its kinda singing the same tune - giving the power back to the users and not storing everything centralised.
This is a direction I am very excited to see develop, as more sites support these mechanisms and we move away slowly from the tradition username/password per service paradigm.